The present invention relates to a cleaning element for brooms or brushes and in particular a cleaning element of the type comprising a plurality of clusters or bundles of fibers engaged in a supporting body.
At present, most cleaning elements of brooms and brushes comprise a supporting body or support which has a surface to which the bundles of fibers, normally bristles, are attached.
The bristles are engaged in relative blind holes made in the supporting body and the set of bundles forms a cleaning unit.
The support, in a variety of shapes, is normally made by molding synthetic material and then processed, in particular holes are drilled in the above-mentioned surface to which the bundles of bristles are attached.
Each of these blind holes forms a seat which houses a single bundle of bristles held together by a fastening element which is normally metal.
Each fastening element is forced, together with part of the bundle, into the respective hole, so as to lock each cluster to the supporting body.
However, this type of production of the cleaning element brings a disadvantage, due in particular to the possible presence of air bubbles in the supporting body, created during the molding cycle.
The bubbles, if present close to the blind holes, may cause a faulty application of the fastening element during penetration or even partial or total yielding of the hole which is no longer able to hold onto the relative bundle, resulting in gaps in the cleaning unit.
To overcome this disadvantage, supporting bodies were studied which have an inner cavity, accessible by the fastening elements by means of through-holes made in the surface for attaching the bundles of bristles.
The cavity normally has a regular contact surface opposite the attaching surface, to deform the fastening elements when they are inserted in the cavity.
In particular, as indicated in the solution described in application WO 03/026460, the supporting element cavity may be formed by two separate bodies, each having a cross-section with the shape of a “U” rotated on one side, assembled by completely inserting the flanges of one, inner body or drawer, between the flanges of the other, outer body.
The two bodies penetrate one another along a direction perpendicular to the direction of longitudinal extension of the holes used to fix the bundles of fibers.
However, the latter solution has some disadvantages.
Due to the low thicknesses involved, the flanges of the drawer may be deformed during molding, making the drawer difficult to insert in the outer body, in particular in the case of very wide supports.
Fixing and bending of the fastening elements in the cavity may not be very precise, since the fastening elements, making impact against the contact surface for deformation, may be diverted and slide along the surface, resulting in locking that is not solid or is imprecise.
Moreover, the relative fixing between the two bodies forming the cavity is preferably achieved by forcing or snapping into place, without guaranteeing suitable holding characteristics.